The present invention relates to a rotary head drum installed in a magnetic tape recording/reproducing apparatus, and particularly to a rotary head drum having a stabilizer for stabilizing the travel of a tape.
In a magnetic tape recording/reproducing apparatus in which a rotary head drum is installed, the recording or reproducing mode is performed such that a tape is drawn out from a tape cassette, and then travels in contact with at least one portion of the rotary head drum's circumferential surface. While this recording or reproducing mode is carried out, if tape vibration occurs (this includes longitudinal vibration in the direction of the tape's width, traversing vibration in the direction of the tape's thickness, and traveling vibration in the direction of the tape's travel), which causes jitter, wow and flutter due to time-base error, thereby deteriorating the recording condition and producing severe noise in the reproduced signal. Especially, longitudinal vibration of the tape causes the scanning path of the head mounted on the rotary head drum to deviate from the signal track of the tape, which in turn affects the envelope of the reproducing signal, causing severe noise.
It is known that an impedance roller is installed in a conventional video tape recorder to prevent the vibration of the tape. Here, the inertia moment of the impedance roller obtained by being rotated while in contact with the tape decreases the high frequency vibration of the tape. However, the impedance roller is installed between the supply reel of the tape and the rotary head drum, which is less effective to prevent the tape from being vibrated on the rotary head drum. Further, since the tape instantaneously contacts the rotary head drum when entering the traveling path, and is instantaneously separated from it while exiting, the tape severely vibrates. Therefore, such vibration is must be further lessened.
To lessen the vibration, a prior art is disclosed in U.S. Pat. No. 4,896,236 entitled "Tape Stabilizer Unit for Stabilizing a Moving Tape in a Tape Recording and/or Reproducing Apparatus." Herein, a stabilizer unit comprising a roller, a circular weight, and a holder for supplying the weight is placed adjacent to a rotary head drum, thereby contriving better stability during the tape's travel. However, since this is also installed separately from the rotary head drum, enough stability to meet the demand in the present invention during the travel of the tape, i.e., the prevention of the tape's vibration on the circumferential surface of the rotary head drum, cannot be expected. Besides, the tape traveling system (particularly tape's loading system) is so complicated that the prior art has disadvantages in several aspects.